Hey guys,
I had the Roush kit installed this week and it's been a bunch of issues. First I had a second battery installed for an audio system that had to come out with the new reservoir and bracket. Not a big deal to move it back out. They had a hard time keeping it 4th gear to do the dyno tuning. They worked with both the LS1Edit and HP Tuners guys and ended up street tuning it. Now they are having problems with it making too much boost. After dyno tuning the kit is making ~11lbs of boost and they don't know why. All the other kits on a 5.3 are making much less boost. Anyone have any ideas?

Matt

 

why dyno in 4th?

and whats wrong with 11psi?

 

sounds to me like your guys don't know what their doing... who did the work? Also, IDK about hpt but with efi live you can command any gear through the scan tool, not that its necessary to dyno tune in 4th gear. I hope they were just working on your VE table, because things can get dangerous on the rollers at that speed. As for the boost, its going to be different with every setup. Are you still running the stock exhaust? Where did you buy your kit, was it used, and what pulley do you have?

 

It is the Roush kit on a completely stock 5.3 09 Avalanche with the 6. Stock pulley. No supporting mods. Brand new kit never seen another vehicle.

Its a very reputable shop known for doing lots of LS and ZR1 work in the Detroit area. They were commanding it to stay in 4th but the transmission was completely ignoring it.

11lbs just seems really high for the numbers I have seen on other 5.3 NNBS trucks.

 

Find another shop, i wouldnt dyno in 4th.


Boost is a measure of restriction, remember.

Im surprised your seeing 11 psi, on a 6.0 you should see roughly half of that.

Your in michigan? Take to TJ at Baker engineering and have it done right.

 

I would have expected 7-9 psi with the stock setup. They said they were down to 9 degrees of timing with the 11 psi blowing through.

They are recommending an LS9 cam, ls7 lifters and springs with kooks 1 7/8 to bring it down and get timing back in.

I might see if TJ can come down as he originally did the tuning on my GTO with individual throttle bodies.

 

if its the 6 speed then 4th is fine. idk why it wouldnt stay in gear if they were commanding it tho.....?

and 11psi is perfectly fine, ive seen more than three times that!! and if theyre down to 9* then id want to find another tuner if i were you! you should easily be able to run twice that..........

 

Seconded

He'll get it figured out. And pretty soon they will be swamped with race cars so now would be the time to have him do it.

 

What size is the pulley?

 

I think the stock Roush is a 3.2 but I could easily be wrong.